Nutty describes something that tastes like nuts (such as almonds, pecans, or walnuts) or has a nut-like flavor. A nutty cheese like Gruyère has a rich, slightly sweet taste that reminds you of toasted nuts. Whole wheat bread often has a nutty flavor compared to white bread. Coffee beans can develop nutty notes when roasted a certain way.

The word also means silly, eccentric, or slightly crazy in a harmless way. Your nutty uncle might wear mismatched socks on purpose and tell jokes that make everyone groan. A nutty idea isn't necessarily bad, just unusual or unexpected. If your friend suggests building a treehouse shaped like a pirate ship, you might call that a nutty plan (even if it sounds fun).

When describing people as nutty, the word is usually affectionate rather than mean. It suggests someone quirky or entertaining rather than seriously unwell. British speakers sometimes use nutty to mean enthusiastic about something, as in “He's nutty about baseball,” though Americans more commonly say “nuts about” instead.